Sunday's win, which gave the Beavers their first series win at Washington State since 2006, marked the 613th for head coach Pat Casey since coming to Corvallis in 1995. That ties Jack Riley for the most in a career at Oregon State.
Conforto's home run was also his 13th of the season, tying him with Al Hunsinger (1980), Gerber (1999), Cole Gillespie (2006) and Stefen Romero (2010) for the fourth-most in a single-season. Conforto needs one to tie Bob McNair (1980) for third-most and is two shy of No. 2 Hunsinger (1981).
Oregon State tallied 15 hits in the win, with Kavin Keyes, Ryan Dunn and Tyler Smith tying for the team lead with three apiece. Max Gordon also had two hits in the win as eight of nine Beavers in the lineup posted at least one.
Danny Hayes extended his hit streak to eight games with a double in the ninth. The designated hitter finished the series 6-for-11 with three home runs and eight RBI.
Gordon drove in the Beavers' (35-18 overall, 15-12 Pac-12 Conference) first run of the game with a double in the third that was hit just inside the first base bag. He moved to third when Tyler Smith reached on an infield single and scored on Conforto's three-run home run.
Dunn added to the Beavers' lead in the fifth when he doubled past the third-base bag, scoring Conforto and Hayes.
Washington State (26-26, 11-16) broke into the Beavers' lead with two sacrifice flies in the fourth for a 4-2 OSU advantage. The Cougars scored their third run when Collin Slaybaugh tripled to center in the fifth, cutting the OSU margin to 6-3.
The Beavers scored one in the sixth and the Cougars tallied solo runs in the seventh and ninth for the 7-5 final.
Dan Child worked eight innings in a start and allowed 11 hits and four runs while throwing 114 pitches. The right-hander struck out two to get the win and improve to 6-3 this season.
Dylan Davis picked up the final out in the ninth for his first career save.
Matt Boyd came in on relief of Child in the ninth and got the first out of the inning before giving way to Cole Brocker, who picked up the second out of the inning. He played first base for the team's second out of the inning, a 4-6 fielder's choice, then allowed a single to Slaybaugh that netted Washington State its fifth run.
Oregon State returns home for its final three games of the season next weekend when hosting Oregon in the Civil War presented by the Northwest Ford Dealers and PacificSource Health Plans. The clubs play at 5:35 p.m. PT Friday to open the series.